• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.598-604
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• 2013

This study was designed to evaluate the usability of the following citrus peel extracts (CPEs): Citrus sinensis (orange), C. unshiu (mandarin orange), C. limon (lemon), and C. paradise (grapefruit) as natural antibrowning agents. Overall, 0.1% of the CPEs were effective in reducing the browning of apple slices. The appearance of apple slices dipped in C. limon peel extracts (LPE) were found to be excellent and their Hunter L and ${\Delta}E$ values were similar to the values obtained when apple slices were dipped in ascorbic acid. The pH values of the different CPEs were not significantly different from each other, but were higher than that of ascorbic acid. LPE was found to possess the highest total phenolic content, flavonoid content, DPPH radical scavenging activity, and copper ($Cu^{2+}$) chelating activity. All these results suggest that citrus peel extracts, especially lemon peel extract, can be used as natural antibrowning agents.

• Analytical Science and Technology
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• v.16 no.4
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• pp.277-282
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• 2003

The amount of water for the cultivation of citrus is different based on the growing period. The effect of water stress induces to enhance of sugar accumulation in citrus. The water content in the leaves of citrus can be a index for watering during cultivation. The purpose of this study is to determine the water content of citrus leaves non-destructively by using near infrared spectroscopy (NIRS). Citrus leaves were prepared from 'Okitsu' Satusuma mandarin leaves (Citrus unshiu Marc.) ranging from 20.80 to 69.98% of water content by loss on drying method, and NIR reflectance spectra of citrus leaves were acquired by using a fiber optic probe. It was found that the variation of absorbance band 1450 nm from OH vibration of water depending on the water content change. Partial least squares regression (PLSR) was applied to develop a calibration model over the spectral range 1100-1700 nm. The calibration model predicted the water content for the validation set with a standard errors of prediction (SEP) of 0.97%. In order to validate the developed calibration model, routine analyses were performed using independently prepared citrus leaves. The NIR routine analyses showed good results with those of loss on drying method with a SEP of 0.81%. The rapid and non-destructive determination of the water content in citrus leaves was successfully performed by portable NIR system.

• Journal of Life Science
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• v.21 no.12
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• pp.1659-1665
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• 2011

In Citrus, an $F_1$ segregation population of 150 plants was constructed from a cross between 'Kiyomi' (C. unshiu ${\times}$ C. sinensis) carrying the male sterility trait and 'Jinkyool' (C. sunki). Sequence-related amplification polymorphism (SRAP) combined with bulked segregant analysis was used to develop markers linked to male fertility. In the $F_1$ population, 66 out of 150 seedlings had aborted anthers and the ratio of male sterile plants to fertile plants in the progenies matched the expected Mendelian segregation ratio of 1:1 ($x^2$ =2.16 at p=0.05). From the profiling of the 197 SRAP primer sets, three SRAP primer sets (F4/R27, F39/R60, and F15/R37) that were closely linked to the target trait were identified and successfully converted into a sequence characterized amplified region (SCAR) marker for selection of male fertility in citrus. The SCAR marker, using the pMS 33U/pMS 1462L primer set specifically, produced a single 1.4-Kb fragment that was linked to male fertility. Our results suggested that this SCAR marker can be useful for marker-assisted selection of male sterile individuals in breeding $F_1$ progenies in Citrus.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.122.2-123
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• 2002

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.04a
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• pp.76.2-77
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• 2005

• Journal of Food Hygiene and Safety
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• v.28 no.4
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• pp.342-348
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• 2013

The following study was presented to investigate the anti-inflammatory effect of peel extracts (PE) from three citrus fruits: Citrus unshiu, Citrus limonia Osbeck and Citrus hallabong. According to this study, cytotoxicity, NO-production and protein levels of iNOS (inducible nitric oxide synthase) in macrophage cell were analyzed, which had been incubated in murine macrophage cell line RAW 264.7 cell of PE from those three citrus fruits. According to Citrus unshiu peel extracts (CUP), Citrus limonia Osbeck peel extracts (CHP) and Citrus hallabong peel extracts (CLP) treatment, the result showed that there was no cell growth inhibited below 2 mg/mL. Comparing the NO-production of the cell with LPS (100 ng/mL) and the treatment without LPS, significant increase of NO-production was detected. However NO-production also showed decrease trend, as the concentration increased. For each treatment, at the concentration of 1 mg/mL, NO-ihibitory activity showed significant result with following order: CUP > CHP > CLP. According to the result from Western blot, the inhibitory activities of iNOS protein from CUP and CHP showed fairly similar performances. Also inhibitory activity of COX-2 showed the following order: CUP > CHP> CLP. There was no doubt that all the treatments of CUP, CHP and CLP have anti-inflammatory effect and also that the inhibitory activity of the CUP treatment was the strongest among those three.

• Korean journal of applied entomology
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• v.50 no.3
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• pp.203-208
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• 2011

This study was conducted to evaluate Geometridae (Lepidoptera) species as pests and the damage they cause in citrus orchards in Jeju, Korea. Seven geometridae species occurred in citrus orchards: Ascotis selenaria, Ectropis excellens, Menophra senilis, Biston panterinaria, Ourapteryx nivea, Odontopera arida and Hypomecis punctinalis. Among them, A. selenaria was most abundant, followed by E. excellens and M. senilis. Most Geometridae larvae fed on citrus leaves, but A. selenaria larvae ate fruits and leaves. Fruit damage of Citrus unshiu appeared as gnawed scars caused by young larvae feeding on fruit surface. Fruit damage on Shiranui fruits appeared as a wide hole or deep scars caused by feeding by mature larvae (6th instar). Citrus leaves damage due to Geometridae larvae was high during May to June. Fruit damage started in late June as the spring-shoots of citrus hardened and increased sharply in late July. In the field experiment, fruit damage in the late season reached 4.2% in both 2008 and 2009 and reached 5.2% in 2010. In citrus orchards, A. selenaria larvae started to appear in mid-May and their populations peaked in mid June, late July, and early to mid-September. Adult males of A. selenaria had a maximum peak in mid-May, and two other peaks in early to late July and late August to early September. A. selenaria male adults were collected in a pheromone traps constantly throughout Jeju Island.

• Food Science and Preservation
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• v.7 no.1
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• pp.44-50
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• 2000

Physicochemical properties and sensory evaluation of Satsuma mandarin produced in Cheju were investigated . Fruit index(width/Length), soluble solids and acid content of Citrus unshiu marc. var. miyagawa(miyagawa) and C. unshiu marc. var.(okitsu) harvested at 1st December were 1.16 and 1.23, 12.12 and 12.01, 0.97 and 1.09, respectively. and the fruit of miyagawa was showed somewhat round in shape, compared to ikitsu. the taste of miyagawa seemed to be better than okitsu. However, compared to miyagawa, peel thickness was thinner, flesh ratio was higher, and firmness was higher as 0.502kg-force in kitsu. Nevertheless there were some differences among panelist groups in sensory evaluation , middle size of citrus fruits were favorable to most panelists, but except very small or very large size of fruits, there were not so much differences in okitsu. The panelists referred to somewhat flat-shaped fruits from that sensory evaluation score was increased to 1.3 in fruit index. nevertheless there were not so much differences in full-colored fruits, the citrus peel color of reddish yellow was more favorable than greenish or pale yellow color. the score was increased more linearly according to citrusfruit produced in optimum ciltivation area, and was prefered to thinner in peel thickness , Correlation between soluble solids, acid content , Brix/acid ratio and flesh ratio with sensory evaluation score were not showed significantly, it was different to with citrus juice. This data obtained in this experiments are supposed to be applied to the quality evaluation of Satsuma mandarin produced in Cheju .

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.184-187
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• 2008

A new early maturing satsuma mandarin (Citrus unshiu Marc.) 'Haryejosaeng' was developed as a nucellar seedling selection of 'Tachima Wase' (C. unshiu Marc.) that was crossed with C. natsudaidai Hayata at the National Institute of Subtropical Agriculture in Jeju island in 1992. The 'Jegam ga No. 2', a first selection from the seedlings fruited in 2001 was finally named "Haryejosaeng" through field evaluation trials at three locations in Jeju island from 2003 to 2004. 'Haryejosaeng' produces seedless fruit maturing in early November, and has higher soluble solids and lower acidity than 'Miyagawa Wase', the leading early-maturing satsuma mandarin cultivar in Jeju island. Fruit weight is moderate at about 80~90 g and its shape is compressed-oblate globose with a light orange color. The rind thickness of about 2 mm provides easy peeling. The flesh shows light orange colored and contains 10 to 11 Brix and 1 to 1.1% acidity when mature. Tree shows vigorous growth and spreading thornless twigs. Alternate bearing is similar to 'Miyagawa Wase'. 'Haryejosaeng' is susceptible to citrus scab disease and melanose, but resistant to citrus canker.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.1084-1089
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• 2015

To develop high quality citrus products, seven lactic acid bacteria were innoculated onto ground citrus (Citrus unshiu) and cultured for 10 days. On culture days 0, 3, 5, 7, and 10, citrus ferments were withdrawn, and their antimicrobial and angiotensin-I converting enzyme (ACE) inhibitory activities were evaluated. Citrus ferments innoculated with CL-1 and CL-2, which were isolated from kimchi, showed relatively higher antimicrobial activities against food poisoning bacteria. Citrus ferments innoculated with CL-1 and CL-2 also showed stronger ACE inhibitory activities than other ferments. CL-1 and CL-2 showed more than 99% homogeny with Pediococcus acidilactici and Lactobacillus sakei, respectively, by 16S rRNA gene analysis. These results indicate that fermentation with P. acidilactici and L. sakei might contribute to the increased antimicrobial and anti-hypertensive activities of citrus.